In court papers filed Tuesday, Laura Wasser, Depp's attorney, accused Heard of refusing to go on the record to testify at a recent deposition.

According to court documents obtained by ET, Wasser claims that Heard appeared nearly two hours late for a court-ordered deposition regarding Heard's request for a permanent domestic violence restraining order against Depp. Wasser claims that instead of testifying, Heard sat with her lawyers and "paced in a separate room." Wasser described Heard as appearing "manic and irrational."

Heard, 30, was granted a temporary restraining order against Depp on May 27, after alleging that Depp was both emotionally and physically abusive towards her throughout their relationship. Wasser has responded to Heard's allegations, claiming that Heard is "attempting to secure a premature financial resolution by alleging abuse."

The case, which is could take several days, is expected to commence on Aug. 17.

Depp's ex, Vanessa Paradis is among the 23 witnesses that Wasser will call upon to support the 53-year-old actor's claim that he did not physically abuse Heard during their time together.

Heard's seven-strong witness list, includes friends Elizabeth Marz and Rachel Pennington, as well as Pennington's fiancé, Joshua Drew. The trio were supposedly in Depp and Heard's apartment building on the night of the alleged attack.